Electronic component package tape and method of manufacturing the same

ABSTRACT

An electronic component package tape comprising a carrier tape of belt-like form storing electronic components in storage pockets formed into a concaved box shape at predetermined pitches, a cover tape of ribbon-like form bonded to the carrier tape to seal upper openings of the storage pockets, and first protrusions, each having a tip of rounded surface formed on an underside surface of the cover tape facing the electronic components. The storage pockets may be provided with a second protrusion formed in an upwardly protruding manner on a bottom surface thereof. In a method of manufacturing the electronic component package tape, the cover tape is held between a first and a second rotating bodies. Both of the rotating bodies are rotated to form protrusions on the cover tape, which is bonded to an upper surface of the carrier tape in a manner to cover openings of the storage pockets.

FIELD OF THE INVENTION

The present invention relates to a belt-like electronic componentpackage tape containing electronic components used primarily forautomated mounting on wiring boards and the like of a variety ofelectronic apparatuses. The invention also relates to a method ofmanufacturing the same.

BACKGROUND OF THE INVENTION

In recent years, automated mounting of electronic components on wiringboards has made considerable progress in manufacture of variouselectronic apparatuses, and there is a continuous rise that suchelectronic components as switches, variable resistors and the likedevices are packed and delivered in the form of package tapes, in whichthe electronic components are stored individually in large number ofstorage pockets in an embossed tape configuration.

Description is now provided of one such electronic component packagetape of the prior art with reference to FIG. 4 and FIG. 5.

FIG. 4 is a sectional view of an ordinary electronic component packagetape. In FIG. 4, carrier tape 301 made of an insulation film in abelt-like form has a plurality of storage pockets 311 of generally aconcaved box shape formed in a consecutive manner at predeterminedpitches. Electronic components 302 such as switches and variableresistors are stored individually in these storage pockets 311 in thesame orientation.

Cover tape 303 of a ribbon-like form made of an insulation film isbonded to an upper surface of carrier tape 301 to seal the openings ofstorage pockets 311. The electronic component package tape is thusconstructed.

The electronic component package tape of this kind is wound into a rollon a reel for transportation (not shown), and packed for storage and thesubsequent shipment. The transportation reel is loaded on an automaticmounting machine (not shown) when electronic components 302 are mountedon wiring boards and the like (not shown) of the electronic apparatuses.

The belt-like electronic component package tape is pulled out of thetransportation reel by the automatic mounting machine, and after covertape 303 is peeled off upward, a suction head (not shown) of theautomatic mounting machine holds and picks up electronic components 302one after another from storage pockets 311 of carrier tape 301, andplaces them in predetermined positions on the wiring boards. Electroniccomponents 302 are hence mounted on the wiring boards by reflowsoldering or the like method.

There occasionally occurs a problem during the automated mountingoperation that electronic component 302 sticks to the underside of covertape 303 and comes out of the carrier tape 301 when cover tape 303 ispeeled off carrier tape 301, if a surface of electronic component 302 isstained with oil or the like substance.

For this reason, cover tape 303 is so formed that the underside surfaceis provided with a plurality of protrusions 332, each having hole 331 inthe center, as shown in the sectional view of FIG. 5, in order thatelectronic components 302 can come into close proximity of protrusions332 having less surface areas to contact instead of the entire surfaceof cover tape 303. The electronic component package tape devised andformed in this manner prevents electronic components 302 from stickingonto the underside surface of cover tape 303 even when electroniccomponents 302 are stained with oil and the like substances, therebyavoiding problems in the automated mounting operation.

One example of the prior art publications known to be relevant to theinvention of this application is Japanese Patent Unexamined Publication,No. H04-31215.

In the electronic component package tape of the prior art, asillustrated above, it is likely that the automated mounting operation isinterfered due to sticking of electronic components 302 when cover tape303 used has a flat surface as shown in FIG. 4. On the other hand, whencover tape 303 is provided with protrusions 332 having holes 331 asshown in FIG. 5 to prevent this problem, there gives rise to anotherproblem that holes 331 in protrusions 332 allow dust and the likeparticles to get into storage pockets 311 during transportation, and thedust enters inside electronic components 302 such as switches andvariable resistors, possibly resulting in malfunctioning of electroniccomponents 302.

SUMMARY OF THE INVENTION

An electronic component package tape of the present invention comprisesa carrier tape of belt-like form storing electronic components in aplurality of storage pockets formed into a concaved box shape atpredetermined pitches, a cover tape of ribbon-like form bonded to thecarrier tape to seal upper openings of the storage pockets, and firstprotrusions, each having a tip of rounded surface, formed on anunderside surface of the cover tape facing the electronic components.

This structure, provided with the protrusions of rounded surface and nohole, prevents dust and the like particles from getting into the storagepockets, and the electronic components from sticking to the undersidesurface of the cover tape due to oil and the like substances, therebyachieving the electronic component package tape capable of ensuringreliable operation of the automated mounting.

Furthermore, a method of manufacturing electronic component packagetapes of the present invention comprises a step of holding a ribbon-likecover tape between a first rotating body having a plurality of convexportions formed at predetermined pitches around the periphery thereofand a second rotating body having concave portions formed around theperiphery thereof in a corresponding manner to the convex portions, astep of forming protrusions of rounded surface on the cover tape byrotating the first rotating body and the second rotating body, and astep of bonding the cover tape formed with the protrusions to an uppersurface of the belt-like carrier tape in a manner to cover openings ofstorage pockets formed in the carrier tape for carrying electroniccomponents.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of an electronic component package tapeaccording to one exemplary embodiment of the present invention;

FIG. 2 is a plan view of the electronic component package tape shown inFIG. 1;

FIG. 3 is a schematic drawing illustrating the steps of manufacturingthe electronic component package tape shown in FIG. 1; and

FIG. 4 and FIG. 5 are sectional views of electronic component packagetapes of the prior art.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

Description is provided of an exemplary embodiment of the presentinvention with reference to FIG. 1 to FIG. 3. FIG. 1 is a sectional viewof an electronic component package tape according to the exemplaryembodiment of this invention, FIG. 2 is a plan view of the electroniccomponent package tape shown in FIG. 1, and FIG. 3 is a schematicdrawing illustrating the steps of manufacturing the electronic componentpackage tape shown in FIG. 1.

According to this exemplary embodiment of the invention in FIG. 1, theelectronic component package tape comprises belt-like carrier tape 11carrying electronic components 2 in a plurality of storage pockets 11Aformed into a concaved box-like shape at predetermined pitches,ribbon-like cover tape 12 bonded to carrier tape 11 to seal upperopenings of storage pockets 11A, and first protrusions 12B havingrounded tips formed on an underside surface of cover tape 12 facingelectronic components 2.

In addition, second protrusions 11B may be formed on a bottom surfacesof storage pockets 11A in a manner to protrude upward.

Description is provided in more detail of the structure of theelectronic component package tape according to this exemplary embodimentof the invention.

Carrier tape 11 is a belt-like form made of an insulation film such aspolystyrene and the like materials. This carrier tape 11 is providedwith a plurality of storage pockets 11A of generally a concaved box-likeshape formed in a consecutive manner at predetermined pitches in alongitudinal direction thereof.

Formed on bottom surfaces of storage pockets 11A are a plurality ofprotrusions 11B (i.e., second protrusions) protruding upward and arecess 11C in the center bottom surface of each of storage pockets 11A.Carrier tape 11 also has sprocket holes 11D formed at predeterminedpitches along one side orthogonal to a widthwise direction thereof.

These storage pockets 11A individually contain electronic components 2such as switches and variable resistors having terminals and controlknobs extending sideway in the same orientation.

Cover tape 12 is a ribbon-like form made of an insulation film such aspolyethylene terephthalate and the like materials. This cover tape 12 isprovided with adhesive layers of a thermo-compression type along sealingareas 12A at both sides of its lower surface, which bond cover tape 12to an upper surface of carrier tape 11 in a manner to seal the upperopenings of storage pockets 11A.

Furthermore, there are a plurality of protrusions 12B (i.e., firstprotrusions), each having a tip of generally a rounded surface formed onthe underside surface of cover tape 12 facing electronic components 2 ina protruding manner with a small space to upper surfaces of electroniccomponents 2. The electronic component package tape is constructed asabove.

In other words, the electronic component package tape of the presentinvention is not provided with any hole in protrusions 12B formed toprotrude on the underside surface of cover tape 12, and this cover tape12 prevents dust and the like particles from getting into storagepockets 11A containing electronic components 2 since it is bonded tocarrier tape 11 along sealing areas 12A at both sides of and covers theupper openings of storage pockets 11A.

In addition, carrier tape 11 is provided with protrusions 11B formedupward on the bottom surfaces of storage pockets 11A. Since protrusions11B make electronic components 2 not liable to stick to the surface ofcarrier tape 11, they help make electronic components 2 easily removablefrom storage pockets 11A during automated mounting, thereby achievingthe automated mounting operation more reliable.

Description is provided next of a method of manufacturing the electroniccomponent package tape of the structure discussed above with referenceto FIG. 3. In order to help make structures of the individual elementsmore comprehensible, FIG. 3 illustrates certain elements with adifferent scale of magnification.

In FIG. 3, first rotating body 13 is provided with convex portions 13Aat predetermined pitches around its periphery. Second rotating body 14has concave portions 14A formed around its periphery in locationscorresponding to convex portions 13A. First rotating body 13 and secondrotating body 14 are so arranged as to face each other with convexportions 13A in engagement to concave portion 14A around theirperipheries, and that both rotating bodies are rotatable in asynchronized motion.

A ribbon-like tape material supplied from the left side of the drawingpasses through the peripheries of first rotating body 13 and secondrotating body 14 as they rotate, while being held between convexportions 13A and concave portions 14A. Hence produced is ribbon-likecover tape 12 formed with protrusions 12B having the tips of generallythe rounded surface at the predetermined pitches.

In this case, cover tape 12 has a thickness not smaller than 50 μm butnot greater than 70 μm, and protrusions 12B of the rounded surfaces areformed into a height not smaller than 0.1 mm but not larger than 0.3 mmat such pitches so that at least two protrusions 12B confront an uppersurface of each of the electronic components.

In this embodiment here, protrusions 12B are not likely to maintaintheir protruding shape because they tend to get flattened if the heightis smaller than 0.1 mm, or protrusions 12B become liable to break andcover tape 12 tend to get wrinkled if the height exceeds 0.3 mm.

In other words, it is desirable to form protrusions 12B of such a heightthat a ratio of the height to the thickness of cover tape 12 generallybecomes not smaller than 1.5 but not larger than 6, and more preferablyin a ratio between 2 and 4.

As an alternative way of forming such protrusions 12B on cover tape 12,there is another method, in which the tape material is supplied by afeeding device to make it pass through intermittently between avertically reciprocating punch and a base plate with a bored holecorresponding to the punch. When compared with this method, however, themethod discussed above for forming protrusions 12B by passing the tapematerial between first and second rotating bodies 13 and 14 can make thecomplex feeding device unnecessary, and form protrusions 12B easily andcontinuously at a faster rate.

Cover tape 12 having protrusions 12B formed in this manner is guideddownward, and placed on top of carrier tape 11 supplied from the rightside of the drawing in a manner that the tips of protrusions 12Bconfront small electronic components 2 such as detector switches storedin a predetermined orientation inside storage pockets 11A.

Following the above, overlapped cover tape 12 and carrier tape 11 passthrough sealing device 15 equipped with a heater (not shown), a presspunch (not shown) and the like, whereby sealing areas 12A on theunderside surface of cover tape 12 are heated and pressed, to completethe electronic component package tape consisting of cover tape 12 bondedto the upper surface of carrier tape 11 containing electronic components2 in its storage pockets 11A.

Electronic component package tape of this type is wound into a roll on areel for transportation (not shown), and packed for storage and thesubsequent shipment. The transportation reel is loaded on an automaticmounting machine (not shown) when electronic components 2 are mounted onwiring boards and the like (not shown) of electronic apparatuses.

The belt-like electronic component package tape is pulled out of thetransportation reel by the automatic mounting machine, and after covertape 12 is peeled off upward, a suction head (not shown) of theautomatic mounting machine holds and picks up electronic components 2one after another from storage pockets 11A of carrier tape 11, andplaces them in predetermined positions on the wiring boards. Electroniccomponents 2 are then mounted on the wiring boards by means of reflowsoldering or the like method.

Since protrusions 12B of generally the rounded surface of cover tape 12confronting upper surfaces of electronic components 2 result inreduction of an area of contact between protrusions 12B and the uppersurfaces of electronic components 2, this embodiment can preventelectronic components 2 from sticking to cover tape 12 when cover tape12 is being peeled off from carrier tape 11 even if electroniccomponents 2 are stained by any chance with oil or the like substance,thereby ensuring reliability of the automated mounting to wiring boards.

Moreover, since the underside surfaces of electronic components 2 are incontact with protrusions 11B on the bottom surfaces of storage pockets11A, which also results in reduction of an area of contact between them,this structure can prevent electronic components 2 from sticking to thebottom surfaces of storage pockets 11A, and help make electroniccomponents 2 easily removable from storage pockets 11A.

According to the present exemplary embodiment, as described, protrusions12B having the tips of generally the rounded surface are formed withouthole on the underside surface of cover tape 12 facing electroniccomponents 2. Protrusions 12B can therefore prevent dust and the likeparticles from getting into storage pockets 11A, and avoid theelectronic components from sticking to the underside surface of covertape 12 due to oil and the like substances, thereby achieving theelectronic component package tape capable of ensuring reliable operationof the automated mounting.

Electronic components 2 such as switches and variable resistors areprovided with moving members like control knobs and the like as comparedwith passive components such as semiconductors and capacitors. It istherefore especially important to keep such mechanical components freefrom dust during transportation and storage because of the possibilitythat intended operation of the moving members is impaired if dustentered into storage pockets 11A reaches inside of the switches and thelike.

The presence of protrusions 11B formed to project upward from the bottomsurfaces of storage pockets 11A of carrier tape 11 reduces the areas ofcontact where the underside surfaces of electronic components 2 restupon these protrusions 11B, and prevents electronic components 2 fromsticking to carrier tape 11. This helps ease the removal of electroniccomponents 2 from storage pockets 11A in the automated mounting, andensures reliable operation of the automated mounting.

In addition, formation of recesses 11C in generally the center of theindividual bottom surfaces of storage pockets 11A also reduces the areaof contact with the underside surfaces of electronic components 2 evenif protrusions 11B become deformed or flattened.

The presence of recesses 11C is also effective for reduction of theareas of contact between the bottom surfaces of storage pockets 11A andthe underside surfaces of electronic components 2 when protrusions 11Bare not provided. Accordingly, recesses 11C make electronic components 2not liable to stick to carrier tape 11, help ease the removal ofelectronic components 2 from storage pockets 11A in the automatedmounting, and thereby they ensure reliable operation of the automatedmounting.

The electronic component package tape can be produced by a simplemethod, in which ribbon-like cover tape 12 is placed between firstrotating body 13 having the plurality of convex portions 13A formed atpredetermined pitches around the periphery thereof and second rotatingbody 14 having concave portions 14A formed around the periphery thereofin locations corresponding to convex portions 13A, and first and secondrotating bodies 13 and 14 are rotated to form protrusions 12B ofgenerally rounded surface on cover tape 12.

The electronic component package tape and the method of manufacturingthe same according to the present invention have an advantageous featureof providing the product that is not likely to allow dust to get intothe storage pockets, and useful for the electronic components and thelike adapted primarily for automated mounting on wiring boards and thelike for use in a variety of electronic apparatuses.

1. An electronic component package tape comprising: a carrier tape ofbelt-like form storing electronic components in a plurality of storagepockets formed into a concaved box shape at predetermined pitches; acover tape of ribbon-like form bonded to the carrier tape to seal upperopenings of the storage pockets; and first protrusions, each having atip of rounded surface formed on an underside surface of the cover tapefacing the electronic components.
 2. The electronic component packagetape according to claim 1, wherein each of the storage pockets isprovided with a second protrusion formed in an upwardly protrudingmanner on a bottom surface thereof.
 3. The electronic component packagetape according to claim 1, wherein each of the storage pockets isprovided with a recess formed in a bottom surface thereof.
 4. Theelectronic component package tape according to claim 2, wherein each ofthe storage pockets is provided with a recess formed in a bottom surfacethereof.
 5. The electronic component package tape according to claim 1,wherein the cover tape has a thickness not smaller than 50 μm but notgreater than 70 μm, the first protrusions have a height not smaller than0.1 mm but not larger than 0.3 mm, and at least two of the firstprotrusions confront an upper surface of each of the electroniccomponents.
 6. The electronic component package tape according to claim1, wherein a ratio of a height of the first protrusions to a thicknessof the cover tape is not smaller than 1.5 but not larger than
 6. 7. Amethod of manufacturing electronic component package tape comprising thesteps of: holding a cover tape of ribbon-like form between a firstrotating body having a plurality of convex portions formed atpredetermined pitches around the periphery thereof and a second rotatingbody having concave portions formed around the periphery thereof inlocations corresponding to the convex portions; forming protrusions ofrounded surface on the cover tape by rotating the first rotating bodyand the second rotating body; and bonding the cover tape formed with theprotrusions to an upper surface of a carrier tape of belt-like form in amanner to cover openings of storage pockets formed in the carrier tapefor carrying electronic components.